It has been common heretofore to provide a base or other fixture which mounts one or more workpiece supports at a machining center, for example, in which a plurality of workpieces may be acted upon simultaneously or sequentially by appropriate machine tools. The workpiece supports conventionally comprise vises, collets, over-center clamps, custom fixtures or a combination thereof. Each of these supports has some drawbacks. For example, vises are bulky and frequently require costly, custom manufactured jaws. Further, some vises are not convenient for holding multiple workpieces at a single machining center. Conventional collets are limited in the sizes of workpieces they can accommodate, thereby requiring a plurality of different size collets to accommodate workpieces of different size. In addition, the length of a workpiece that can be accommodated in a collet often is limited to approximately the length of the collet itself.
Over-center clamping devices are of limited flexibility and have limited clamping ability. In addition, over-center clamps require that they be of fairly precision design to ensure proper functioning.
Custom fixtures require design adaptation for specific workpieces, thereby increasing their cost. In addition, it is necessary to change custom fixtures when the workpieces at a machining center are changed from one kind to another.
Among the objects of the invention is the provision of apparatus which overcomes or substantially minimizes the objectionable characteristics referred to above.